Electronic device

Abstract

An electronic device comprises means for manually entering information relating to the battery and means for informing the exchange time of the battery in relation to said manual entry means.

What I claim is: 
     
       1. An electronic device powered by a battery, comprising: a set of numeral keys for entering numerical information relating to the expected useful lifetime of the battery;   memory means connected to said set of numeral keys for storing therein the numerical information;   calculation means for calculating the time from insertion of the battery into said device to the end of the expected useful lifetime of the battery;   comparison means for comparing the numerical information stored in said memory means with the time calculated by said calculation means; and   digital display means responsive to said comparison means for visually displaying numerical information indicative of the remaining useful lifetime of the battery.   
     
     
       2. A device according to claim 1, wherein said electronic device includes a desk-top electronic calculator and wherein said digital display means includes a digital display device for use in the desk-top electronic calculator. 
     
     
       3. A device according to claim 1, wherein said electronic device includes a digital timepiece and wherein said digital display means includes a digital display device for use in the timepiece.